1. Technical Field
The present invention relates to a liquid ejecting apparatus, and in particular, relates to a technique of transporting a recording medium onto which liquid has been ejected.
2. Related Art
A liquid ejecting apparatus which forms (records) a predetermined image (including a character, a figure, and the like) on a recording medium as follows has been known. That is, in the liquid ejecting apparatus, liquid (for example, ink) is ejected onto a recording medium (for example, paper) or the like from a liquid ejecting head and is adhered thereto so that a predetermined image is formed. A discharge unit is normally provided on such liquid ejecting apparatus. The discharge unit discharges a recording medium to which liquid has adhered in a recording unit provided in the liquid ejecting apparatus onto a placement table or the like provided outside the liquid ejecting apparatus. Further, a transportation path is formed in such liquid ejecting apparatus. The transportation path is a path for transporting a recording medium to which liquid ejected from a liquid ejecting head in the recording unit has adhered from the recording unit to the discharge unit.
Such transportation path is provided such that a passage in the transportation path has a substantially semicircular arc shape in order not to increase a liquid ejecting apparatus in size when seen from above. That is to say, a recording medium is transported along the transportation path of which passage in the transportation direction has a circular arc shape as described above. Therefore, front and back surfaces of the recording medium are reversed on the way of the transportation, and then, the recording medium is discharged. As a result, a placement table can be arranged so as to be superimposed with the recording unit on which a liquid ejecting head is provided when seen from above. This can realize the liquid ejecting apparatus to be reduced in size when seen from above. Various liquid ejecting apparatuses including a transportation path of which passage in the transportation direction has a substantially circular arc shape in order to reduce the liquid ejecting apparatuses in size as described above have been proposed (for example, JP-A-2005-89125).
However, when a transportation path which is curved and of which passage in the transportation direction has a substantially circular arc shape (in particular, semicircular shape) (the transportation path is also referred to as “curved transportation path”) is employed, there arises a following problem. That is, when a recording medium is transported, a transportation resistance is unfortunately large in such curved transportation path in comparison with a case where a linear transportation path is employed. Note that the linear transportation path is a path of which passage through which a recording medium passes is not curved or is less curved with a large curvature. For example, a recording medium in a flat state passes through the curved transportations path, a curvature of the recording medium which is curved along the transportation path is different from (normally, larger than) that of the curved transportation path. Therefore, friction is generated between a wall surface of a passage (in particular, wall surface at the center side of a circular arc) and the recording medium so as to cause increase in a transportation resistance. Further, in a case where a transportation distance from a recording unit on which a liquid ejecting head is provided to a discharge unit is short or the like, a recording medium may pass through the curved transportation path in a state where liquid adhered to the recording medium is undried. In such a case, for example, a recording medium passes through the curved transportation path in such a state that a portion of the recording medium to which undried liquid has adhered is deformed. Therefore, the recording medium makes contact with a passage wall surface so that a transportation resistance becomes large in some case.
Then, in order to address the above cases, the following technique has been proposed (for example, JP-A-10-193722). With the technique, the air flows in a direction along the transportation direction on a transportation path of a recording medium. Therefore, liquid in an undried state is dried and a recording medium is smoothly transported to a discharge unit.
However, when the air flows in the direction along the transportation direction, an effect of drying liquid in an undried state can be expected but an effect of generating a force acting on a recording medium in the direction that the recording medium is bent cannot be expected in principle. Accordingly, it is difficult to match a curving manner of a recording medium passing through a curved transportation path with that of a curved transportation path. Therefore, there remains a problem that a transportation resistance is still large.